Coverslipping machines are used in histology in order to coverslip specimen slides on which, for example, tissue sections are located. It is known for this purpose to apply a mounting medium (a kind of liquid adhesive) in metered fashion onto the specimen slide by means of a hollow needle, and then to press on a coverslip for sealing. A coverslipping machine of this kind is marketed, for example, by the Applicant under the designation “Leica CV5030.”
When the coverslipping machine is not in use, or during stoppage times, the risk exists that the mounting medium may dry out in the hollow needle and thereby clog it. Depending on the ambient temperature, mounting medium can already begin to dry in only a few minutes. To decrease this risk, DE 10 2005 020 426 A1 describes a cleaning device for the hollow needle which comprises a brush and a solvent container connected to the brush. The hollow needle is inserted into the solvent-wetted brush for cleaning.
In light of this existing art, automatic limit level detection e.g. for the solvent is desirable. This allows drying of the cleaning device to be avoided. The measures should be easy to implement but nevertheless robust and reliable, in order to function dependably over a long period of time even in a laboratory environment.